For an air conditioner which air-conditions the inside of a hybrid vehicle that uses an engine and an electric motor as a driving source, a technology that improves comfort by pre-air conditioning the inside of the vehicle during engine stop before a vehicle occupant boards the vehicle has been proposed. This type of the conditioner for vehicles air-conditions the inside of the vehicle by, for instance, driving a compressor by electric power from a battery. Therefore, a control is required to prevent excess battery discharge.
Accordingly, JP-A No. 2004-230936 proposes an air conditioner for vehicles that prohibits pre-air conditioning when battery voltage is lower than a predetermined value during engine stop even if it is anticipated that a vehicle occupant is going to board the vehicle within a predetermined time. As a result, excess discharge of the battery can be inhibited.
Furthermore, an air conditioner according to JP-A No. 2002-219926 includes a fuel cell and performs pre-air conditioning using electric power from the fuel cell. The air conditioner prohibits execution of pre-air conditioning when the remaining capacity of the fuel cell is low.
However, in some cases, with the technologies disclosed in the JP-A No. 2004-230936 and JP-A No. 2002-219926, the vehicle occupant may not be able to operate the pre-air conditioning even if they want to. Therefore, the probability that pre-conditioning will be executed is reduced, thereby causing the problem that there are an increased number of cases when the inside of the vehicle cannot be maintained in a comfortable state.
The present invention has been devised in consideration of the aforementioned circumstances, and it is an object of the invention to provide an air conditioner that increases the probability that pre-air conditioning will be executed and that inhibits an increased occurrence of a situation in which the inside of a vehicle is not in a comfortable state before a vehicle occupant boards the vehicle.